This species resembles T. divaricatus in many respects; however, T. paradoxus is generally smaller and lacks a peristome. The spores of this species also approach those of T. divaricatus, but they are not as highly ornamented and the tetrad scar is weak, when present.
Plants very small, in scattered groups, green; terricolous. Stems 1-2 mm high; in section central strand small, inner cortical cells large, thin-walled, outer cortical cells in 2 rows, small, incrassate, red. Leaves erect, weakly flexuose dry, erect-spreading wet; oval to oblong, abruptly linear, 1.5-2.0 mm long; apex obtuse, occasionally acute; margins plane, entire, unistratose. Costa sub-percurrent, in section guide cells 4, exposed ventrally, dorsal stereid band 1-2 cells thick, dorsal surface cells larger, weakly thickened, occasionally extending upward interrupting stereid band. Laminal cells bulging, rectangular above shoulders, in 1-3 rows on either side of costa at apex; marginal cells bulging; basal cell long-rectangular or oblong-hexagonal, lax. Perichaetial leaves oblong-subulate, 2.0-2.5 mm long. Seta erect to flexuose dry, 2-3 mm long, yellow; capsule erect, yellow, urn 1 mm long, neck 0.8-1.0 mm long, strumose; peristome absent; operculum rostrate, 0.6-0.8 mm long; calyptra cucullate, covering operculum and capsule mouth; spores ± round, 30-35 µm, coarsely papillose.
Plants very small, in scattered groups. Stems 1-2 mm long. Leaves erect to erect-spreading, oval to oblong, abruptly linear, 1.5-2.0 mm long; apex obtuse to acute; margins entire, unistratose; costa subpercurrent. Laminal cells bulging, rectangular; basal cells lax. Capsule erect, neck strumose; peristome absent. Spores round, coarsely papillose.
Known from the Central African Republic, Zimbabwe and South Africa, Trematodon paradoxus was described from Table Mountain. Additional material from the southwestern Cape has not been seen. Recent specimens have been collected in the southeastern Transvaal, eastern Orange Free State, Zululand, Natal, and the eastern Cape.